Hot water heater



AprilZ, 1940. H.D. sTERlcK 2,195,878

HOT WATER HEATER Filed 0G11. 29, 1937 BY MAM AToRNEY. l

Patented IApr. 2, 1940 UNITED STATES PATENT OFFICE HOT WATER HEATER Harrison D. ASterick, Pittsburgh, Pa.

Application October 29 4 Claims.

This invention relates to new and useful improvements in instantaneous water heating and storage systems, and it is among the objects thereof to provide a system of the above-designated character, which shall be especially adapted for use in automobile trailers, cottages and the like, where compactness and economyv of gas and space is a primary consideration.

It is a further object of the invention to provide hot water heating and storage systems of a construction to eiciently andI economically heat water by providing maximum area for heat absorption within a minimum space, and which shall substantially eliminate dripping incident to the so-called sweating of the heating pipes and heater housing.

Another object of the invention is the provision of a water heating system comprising an outer and inner housing, in `which the inner housing is intimately engaged by a water heating coil in the form of helical convolutions.

Still a further object of the invention is the provision of a water heating system comprising a plurality of helically formed heating coils disposed one within the other with a housing interposed therebetween and having a combustion chamber in the bottom thereof, from which the products of combustion are directed in intimate contact with the convolutions of the inner coils.

'I'hese and other objects of the invention will become more apparent from a consideration of the accompanying drawing constituting a part hereof in which like reference characters designate like parts and in which:

Fig. 1 is a vertical cross-sectional view of a heater housing showing the water heating and circulating coils and storage tank in side elevation; and

Fig. 2 is a similar view of a modified form of the heater shown in Fig. 1. f

In Fig. 1 of the drawing, the structure therein illustrated comprises a base I of cast metal having a radial iiange 2 on which is mounted a burner 3, and a flange 4 for supporting an inner shell 5 and a shell 6, the outer shell or housing 'I being supported in a recess 8 formed by the divergent flange or rib 4 of the base I. The inner shell 5 is provided with legs or a scalloped or fluted base to permit heat from the burner to boil or evaporate any moisture accumulating on the outside of the tapered housing 6 to pass into a sweat band 9 formed around the base of the inner housing 5. The tapered housing 6, in effect, constitutes a re box or heating chamber, which is designated by the reference numeral I 0, in

, 1937, Serial N0. 171,646

which is disposed the heater coil I I that extends from a T-connection I2 leading to the service line I3 upwardly into the combustion chamber I il, thence above the housing 6 to the top of the heating unit. A cover I4 having flange I5 caps the outer housing 1, and perforations I5 are provided at the top of the inner housing 5 to permit circulation of air from between the walls 5 and 'I into the top of inner chamber and from there to stack. The top I4 is provided with a hanged opening I'I to permit exit of the products of combustion.

Disposed in the upper portion of the inner housing is a hot water storage tank I8, having an outlet connection I9 to the heating coil II, the connection I9 extending into tank .I8 a substantial distance and terminating adjacent the bottom of the tank I8. Tank I8 is also provided with a cold water inlet connection 20 having a coil 2| that is coiled or wrapped around the inner housing wall 5 to the lowermost position of the heater coil II, and is then coiled or wrapped upwardly or doubled upon itself and terminates at a connection 22 leading to a source of cold water supply.

The burner 3 is connected to a gas line 23 having a thermostat 24 connected in the heating coil to render the burner responsive to the temperature variations of the hot water flowing to the service line. A feature of the invention is the provision of a plurality of relatively long ns 25 in the form of a spiral, in which the heater coil I I is wrapped or brazed as shown in dotted lines at 26, and from which the coil extends upwardly between the inner housing wall 5 and the wall of the water storage tank I8 to the connection I9 leading into the tank.

A baiiie plate 25a is disposed beneath the ns 25,`the plate functioning to divert the'products of combustion from the center against the sidewalls of the burner housing 6 to thereby eiect intimate contact of the hot gases with the heating coil I I. The tapered housing 6 terminates in an inclined flange 6a which collects the moisture dripping from the storage tank I8 and diverts it away from the inner heating coil into the drip pan 9.

The inner heating coil II or the outer coil 2| may be intimately attached to the housings 5 and B as by brazing to effect a more eflicient exchange or transfer of heat with the water in the coils.

In the construction shown in Fig. 2 of the drawing, the base and housings are substantially as shown in Fig. 1 with the heater coil in the form of ark series of spirals around the storage tank IB. This construction differs also from that of Fig. 1 in that the cold water inlet designated by the numeral 2'I is at the bottom of the heater instead of the top, as shown at 22 in Fig. 1, and the cold water supply line extends in one direction only, upwardly around the inner housing wall 5, to the top of the storage tank.

The construction of Fig. 2 provides more capacity than that of Fig. 1 but is in principle the same as that shown in Fig. 1 with the exception of the single instead of double coiling of the cold water supply line.

The operation of the hereinbefore described,

instantaneous and storage water heating system is briefly as follows: 'With the burner 3 supplying the eiective heating temperature in the fire box chamber Ill, water in the heater coil I I is heated and rises upwardly into storage tank I8, in which it circulates so that the tank E8 at all times contains hot water. As the water is drawn from the service line I3, it will pass from the storage tank Ill through the outlet connection I9 downwardly through the heater coil, around the storage tank I8, thence into the spiral iin structure 25 and down through the nre box It where the temperature of the water is increased before it passes through the service line I3 to use. As the available supply of hot water in tank I S is diminished, the temperature will drop in the heater coil II and thermostat 24 will increase the fuel supply to the burner 3 to make up the diierence in the temperature drop, thereby continuing the supply of water at the desired temperature for an indenite period. However, the storage tank I8 is of such capacity as to furnish a normal demand for hot water at all times without requiringr increased consumption of fuel by the burner 3. The feature of the thermostat control is provided to take care of unusual conditions when the heating apparatus is subject to overload.

It will be noted that by the disposition of the heating coil within the housing or re box I Il and the substantial lling of the space at the top of the rebox housing 6, all the heat in the iire box is absorbed by the coil. However, any heat passing through the central opening of the iin 25 will again contact both the wall of the storage tank I8 and the hot water coil II, which pre-- vents a straight line ue action of the heat and products of combustion to the stack II. This function may be accomplished by use of a dry housing of the shape of tank I8 where the system is used only as an instantaneous heater. Furthermore, the heat absorbed by the inner housing 5 will be conducted to the cold water supply coil 2 I, which is wrapped around the inner housing 5 so that maximum heat absorption is obtainable by the arrangement of the hot water and cold water coils, as shown and described.

The space between the outer housing 'I and inner housing 5 permits circulation of air to prevent sweating on both the inner and outer housing walls 5 and and any moisture accumulating on the wall 5 will iiow downward into the sweat band 9. Likewise any sweating on the housing 6 of tho combustion chamber will accumulate in the sweat band 9 from which it evaporates and passes into the stack I'I through the space between inner housing 5 and outer housing 1.

It will be evident from the foregoing description of the invention that hot water heating systems made in accordance therewith provide maximum heating capacity within a minimum space and with a minimum cost for fuel. It also prevents dripping caused by so-called sweating and provides an ideal system for use in trailers or the like.

Although one embodiment of the invention has been herein illustrated and described, it will be apparent to those skilled in the art that various modications may be made in the details of construction without departing from the principles herein set forth.

I claim:

l. In a hot water heating and storage system, a base suppoiting a burner, an inner housing open at the top forming a combustion chamber supported on saidbase, an outer housing supported on said base and an intermediate housing supported on said base, a heating coil disposed in the combustion chamber formed by the inner housing, a storage tank suspended in the top of the intermediate housing, the heating coil' extending beyond the combustion chamber and passing around the storage tank to a connection leading to said tank in the top thereof, a cold water supply line connected to the top of the storage tank and having its convolutions disposed intermediate the outer housing and inner housing walls out of contact with the heating coil, said water supply coil extending downwardly and upwardly a clistance coextensive with the heater coil and connected to a source of water supply at the top of the heating and storage system.

2. In a hot water heating system, a housing forming a combustion chamber, a second housing disposed around said first named housing and an outer housing disposed around the second-named housing, the housing constituting the combustion chamber being of substantially half the length of the other housings, a heating coil extending upwardly in intimate Contact with the inner wall of the combustion chamber and above the combustion chamber in intimate contact with the inner wall of the second-named housing, and a coil extending substantially the full length of the outer wall of the second named housing.

3. A water heater as set forth in the next preceding claim having a sweat box disposed between the outer and intermediate housing at substantially the base of said housings.

4. In a hot water heating and storage system, the combination of a heating coil, a storage tank disposed within said coil, said coil being partially wrapped around said storage tank in helically wound superposed layers and connected to an outlet in said tank, a cold water coil leading to a source of water supply connected to the top of the storage tank and having its convolutions disposed outside of the heating coil a distance coextensive with the heating coil, a housing dividing the water supply and heating coil, and a housing disposed around the water supply coil, a heaterv at the bottom of said coils and a baille interposed intermediate the top and bottom extremities of the heating coil, said bale comprising a spiral n in which the heating coil is disposed between the convolutions of the ln to constitute the upper limits of a combustion chamber,

HARRISON D. STERICK. 

